Allow queuing "pull lever" jobs directly from buildings linked to levers

[chdoc]

Adding a button to the details window of buildings linked to levers (e.g. a bridge) that would queue the "pull lever" job on the linked lever would be convenient.

[myk002]

Note to imlementor (self?) -- code for creating a pull lever job is already in lever. we'd just need a simple UI that links up the functionality